Objective To investigate the value of high-dose dobutamine stress echocardiography combined with two-dimensional strain imaging in early diagnosis of coronary artery disease. Methods Highdose dobutamine stress echocardiography was performed to 28 patients with suspected coronary artery disease. All wall movements were observed during resting condition and at all stress levels,respectively;the peak systolic longitudinal strain in each endomyocardial segment of left ventricular was measured; the sensitivity and specificity between visual method and two-dimensional strain imaging in diagnosing myocardial ischemia with high-dose dobutamine stress echocardiography were compared. The average peak systolic longitudinal strain was calculated against control group, coronary artery disease group during ischemia segments and non-ischemia segments, and a comparison was made inside each group as well as against the other groups. The area under receiver operating characteristic curve of the peak systolic longitudinal strain was used to predict the sensitivity and the specificity of myocardial ischemia. Results With dobutamine dose of 40 μg·kg-1 · min-1 ,wall motion abnormalities were diagnosed in 6 patients (20 segments) through visual method, myocardial ischemia was found in 15 patients (148 segments) through computing the peak systolic longitudinal strain. Inside the coronary artery disease group during ischemic　segments,the majority of peak systolic longitudinal strain was significantly reduced ( P＜0.05) compared to the non-ischemic segments and the control group. In diagnosing myocardial ischemia in high-dose dobutamine stress echocardiography, the sensitivity of visual method and two-dimensional strain imaging were 35.3％ and 88.2％(P＜0.01), specificity 100％ and 100％(P＞0.05), and accuracy 60.7％ and 92.8％ (P＜0.01). The cutoff value of the peak systolic longitudinal strain was less than or equal to 14.9％, its sensitivity and specificity in predicting myocardial ischemia were 83.3％ and 91.7％,respectively. Conclusions High-dose dobutamine stress echocardiography combined with two-dimensional strain imaging can increase the sensitivity of detecting myocardial ischemia and detect concealed myocardial ischemia. High-dose dobutamine stress echocardiography combined with two-dimensional strain imaging can be used in early diagnosis of coronary artery disease.

Objective To investigate the value of myocardial contrast echocardiography(MCE)combined with high-dose dobutamine stress echocardiography(DSE)in the early diagnosis of coronary artery disease(CAD).Methods The dobutamine stress MCE and SonoVue contrast infusion were performed before an elective percutaneous coronary intervention in 38 patients with suspected CAD.The total and regional perfusion were scored as normal or abnormal and attributed to the three main epicardial coronary arteries using a 16-segment left ventricular model.Results An intermediate stress level was obtained in 22(58%)patients,and 9(24%)patients were obtained with peak stress.Twenty seven of 38 patients were diagnosed as CAD by quantitative coronary angiography.A perfusion defect was detected in 89% of the patients at peak stress,compared to 37% at baseline,there was significant difference(χ2=15.565,P<0.01).ConclusionsThe MCE combined with DSE can increase the sensitivity of myocardial ischemia detection.As a new non-invasive method,MCE combined with DSE could be used in the early diagnosis of CAD.